This invention relates to solutions of neutral substituted or unsubstituted polyanilines and to methods of forming such solutions. Another aspect of this invention relates to a method of using such solutions to form polymer articles, such as films, printings, coatings and parts.
2. Prior Art
There has recently been an increased interest in the electrochemistry and electrical phenomena of polymeric systems. Recently, work has intensified with polymers having extended conjugation in at least one backbone chain.
One conjugated polymer system currently under study is polyaniline. Kobayashi, et al., J. Electroanal, Chem., "Electrochemical Reactions Concerned With Electrochromism of Polyaniline Film-Coated Electrodes", 177, 281-291, (1984) describes various experiments in which spectro-electrochemical measurements of a polyaniline film coated electrode were made. French Patent No. 1,519,729; French Patent of Addition 94,536; U.K. Patent 1,216,549; "Direct Current Conductivity of Polyaniline Sulfate", M. Doriomedoff, F. Kautiere-Cristofini, R. De Surville, M. Jozefowicz, L-T. Yu, and R. Buvet, J. Chim. Phys. Physicohim. Brol. 68, 1055 (1971); "Continuous Current Conductivity of Macromolecular Materials", L-T. Yu, M. Jozefowicz, and R. Buvet, Chim. Macromol., 1, 469 61970); "Polyaniline Based Filmogenic Organic Conductive Polymers", D. LaBarre and M. Jozefowicz, C. R. Acad. Sci., Ser. C. 269, 64 (1969); "Recently Discovered Properties of Semiconducting Polymers", M. Jozefowicz, L-T. Yu, J. Perichon, and R. Buvet, J. Polym, Sci. Part C, 22 1187-1195 (1969); "Electrochemical Properties of Polyaniline Sulfates:, F. Cristofini, R. DeSurville, and M. Jozefowicz, C. R. Acad. Sci., Ser. C. 268, 1346 (1979); "Electrochemical Cells Using Protolytic Organic Semiconductors", R. De Surville, M. Jozefowicz, L-T. Yu, J. Perichon, R. Buvet, Electrochem. Ditn., 13, 1451 (1986); "Oligomers and Polymers Produced by Oxidation of Aromatic Amines", R. De Surville, M. Jozefowicz, and R. Buvet, Ann. Chem. (Paris), 2, 5 (1967); "Experimental Study of the Direct Current Conductivity of Macromolecular Compounds", L-T. Yu, M. Borredon, N. Jozefowicz, G. Belorgey, and R. Buvet, J. Polym. Sci, Part C., 16, 2931 (1967); "Conductivity and Chemical Properties of Oligomeric Polyaniline", M. Jozefowicz, L-T. Yu, G. Belorgey and R. Buvet, J. Polym. Sci., Part C., 16, 2943 (1967); "Products of the Catalytic Oxidation of Aromatic Amines", R. De Surville, M. Jozefowicz, and R. Buvet, Ann. Chem. (Paris), 2, 149 (1967); "Conductivity and Chemical Composition of Macromolecular Semiconductors", Rev. Gen. Electr., 75, 1014 (1966); "Relation Between the Chemical and Electrochemical Properties of Macromolecular Semiconductors", M. Jozefowicz and L-T. Yu, Rev. Gen. Electr., 75, 1008 (1966); "Preparation, Chemical Properties, and Electrical Conductivity of Poly-N-Alkyl Anilines in the Solid State", D. Muller and M. Jozefowicz, Bull. Soc. Chem., Fr. 4087 (1972).
U.S. Pat. Nos. 3,963,498 and 4,025,463 describe oligomeric polyanilines and substituted polyanilines having not more than 8 aniline repeat units which are described as being soluble in certain organic solvents and which are described as being useful in the formation of semi-conductor compositions having bulk electrical conductivities up to about 7.times.10.sup.-3 S/cm and, surface resistivities of 4.times.10.sup.7 ohm/square. European Patent No. 0017717 is an apparent improvement in the compositions of U.S. Pat. Nos. 3,963,498 and 4,025,463 and states that the polyaniline can be formed into a latex composite through use of acetone solutions of the oligomers of polyaniline and suitable binder polymers.
U.S. Pat. No. 4,855,361 describes a conductive polymer blend which comprises mixing a polyamide with a base-type polymer containing carbon nitrogen linkages, such as polyaniline, having a polyamide-like group covalently linked to the nitrogen atoms of the base-type polymer. The conductive polymer blend is formed by first reacting a base-type non-conductive polymer containing carbon-nitrogen linkages, such as polyaniline, with a carbonyl anhydride, such as 3,4, 3',4'-benzophenone tetracarboxylic dianhydride to form a conductive polymer containing polyimide-like groups covalently linked to the nitrogen atoms of the base-type polymer, mixing such conductive polymer with non-conductive polyamide in a suitable solvent, removing the solvent, and forming a conductive continuous phase blend of the polyamide and the conductive polymer.
U.S. Pat. No. 4,798,685 describes the production of base-type conductive polymers, particularly from the family of conductive polyaniline, by reacting a base-group non-conductive polymer containing carbon-nitrogen linkages, e.g. polyaniline,with an R.sup.+ donor compound, where R is an organic group, e.g. methyl iodide, and forming an electrically conductive polymer in which the R groups are covalently linked to the nitrogen atoms of the polymer.
U.S. Pat. No. 4,806,271 describes the production of base-type conductive polymers, particularly from the family of conductive polyaniline, by reacting a base-type non-conductive polymer containing carbon-nitrogen linkages e.g., polyaniline, with a cation donor compound, such as R.sub.2 SO.sub.4, R'SO.sub.2 Cl or R".sub.3 SiCl, where R, R' and R" are alkyl or aryl, such as dimethyl sulfate or tosyl chloride, and forming an electrically conductive polymer in which the R groups of R.sub.2 SO.sub.4, the R'SO.sub.2 groups of R'SO.sub.2 Cl, or the R".sub.3 Si groups of R".sub.3 SiCl are covalently linked to the nitrogen atoms of the polymer.
U.S. Pat. No. 4,822,638 describes a process for fabricating an electronic device on a non-conductive polymer substrate, particularly from the family of polyaniline, which comprises applying a covalent doping agent, such as an R+ donor compound, where R is an organic group, e.g., methyl iodide, to a preselected portion of a base-type non-conductive polymer substrate containing carbon-nitrogen linkages, and converting such preselected portion of the polymer substrate to an electrically conductive polymer portion, by covalent linkage of the R groups of such donor compound, to the nitrogen atoms of the non-conductive polymer substrate. Electronic devices, such as resistors, capacitors, inductors, printed circuits and the like, can be provided by the invention process, in the form of light-weight polymers containing no metal, and which are stable and wherein the conductive portions are non-diffusing.
U.S. Pat. No. 4,851,487 describes the Production of base-type conductive polymers, particularly from the family of conductive polyaniline, by reacting a base-type non-conductive polymer containing carbon-nitrogen linkages, e.g., polyaniline, with an anhydride such as R--SO.sub.2 --O--SO.sub.2 --R',R--CO--O--CO--R' or R--CO--O--SO.sub.2 R or mixtures thereof where R and R' are alkyl or aryl, e.g., tosylic anhydride or benzophenone tetracarboxylic dianhydride, and forming an electrically conductive polymer in which the SO.sub.2 R and COR groups are covalently linked to the nitrogen atoms of the conductive polymer and the anion of the conductive polymers is the RSO.sub.3.sup.- or R'CO.sub.2.sup.- group.
U.S. Pat. No. 4,798,685 describes the production of base-type conductive polymers, particularly from the family of conductive polyaniline, by reacting a base-type non-conductive polymer containing carbon-nitrogen linkages, e.g., polyaniline, with an R.sup.+ donor compound, where R is an organic group, e.g., methyl iodide, and forming an electrically conductive polymer in which the R groups are covalently linked to the nitrogen atoms of the polymer.
PCT W089/01694 describes various electrically conductive polyanilines doped with certain sulfonated dopants. These materials are disclosed as thermally stable and capable of being melt blended to form blends with other types of polymers.
Several solvents for neutral (undoped) polyaniline are known. For example, F. Wudl et al., J. Am. Chem. Soc., 109, 3677(198) disclosed dimethylformamide as a solvent for polyaniline base. U.S. Pat. No. 4,913,867 discloses N-methyl pyrrolidone as a solvent for polyaniline, and A. MacDiarmid, et al. Polym. Preprints, 30, 147 (1989) disclosed N-methylpyrrolidone as a solvent for the neutral reduced (leuco) form of polyaniline. Similarly, X. Tang et al. Makroml. Chem. Rapid Commun., 9, 829-834 disclose N-methylpyrrolidone and dimethylformamide as solvents for high molecular weight polyaniline and tetrahydrofuran as a solvent for low molecular weight polyaniline. A. G. Green and A. E. Woodhead, J. Chem. Soc., 2388(1940) discloses pyridine as a solvent for neutral polyaniline, but indicates that such solutions are unstable. M. Angelopoulos, et al. Mol. Cryst. Lig. Cryst. Bulletin. p 240 (1988) discloses dimethyl sulfoxide, dimethylformide, and N-methylpyrrolidone as solvents neutral polyaniline and M. Inoue et al. Synth. Met., 30, 199(1989) discloses dimethylsulfoxide, ethanol and chloroforam as solvents for specially prepared "soluble" polyaniline base described as unbranched and uncrosslinked.